NHS-activated Peptide Conjugation Magnetic Beads

Magnetic bead peptide pulldown

Click here for the Maleimide-Activated Magnetic Beads.

Faster Magnetic Response; Simpler Protocols;

LifeTein’s unique coupling chemistry enables fast and efficient covalent conjugation of amino (-NH2) and thiol (-SH) containing proteins and peptides, to the solid core with iron oxide clusters. All steps in the coupling are performed at physiological conditions and at room temperature with high yields and short reaction times. The magnetic product consists of nano-superparamagnetic beads, which are functionalized with high-density maleimide groups. The beads are used to couple thiol-containing ligands such as peptides, proteins, antibodies, and aptamers. Subsequently, target proteins are easily separated from the solution using a magnet for downstream experiments. 

The magnetic beads show superior magnetic behavior and are easily attracted to external magnets allowing separation within seconds. The matrix enables minimal nonspecific binding of proteins due to its hydrophilic nature. The beads are black and easily observed by the eye and dense, making them easy to spot and collect. The beads do not aggregate and are easily re-suspended in most buffers.

The coupling capacity is generally 1-10 mg protein or 0.1-1mg peptide/ml beads.

The number of beads needed can easily be scaled up or down to match antibody concentration and sample volumes. The beads are suitable for separations from the ul to 500 ml scale using appropriate magnetic separators.

NHS-Activated Magnetic Beads are uniform, silica-based superparamagnetic beads coated with high-density NHS (N-hydroxyl-succinimide) functional groups on the surface. The beads are used to specifically conjugate primary Amine-containing ligands, so other active groups in the ligand do not need to be protected before coupling. Coupling is fast (15–30 min at room temp pH 6.5–9, 4 hours at 4 °C). The NHS-activated Magnetic Beads are most suitable for the conjugation of peptides and proteins.

Magnetic bead
Catalog Number:
Packing Details:
30mg in 20% ethanol

The magnet is not provided.

Binding Capacity:
1-10 mg protein or 0.1-1mg peptide/mg maleimide magnetic beads.
Particle size:
500nm diameter
Coupling conditions:
10mM pyridine
Coupling capacity:
1-10 mg protein or 1 mg peptide/mg beads.

Coupling capacity was determined by incubating 30mg beads with human lgG (1 mg/ml in 1ml PBS) for 60 minutes at room temperature.

Product shipped at room temp. Upon receipt, please store at 2-8°C.
Shelf Life:
Stable for at least two years
Recommended Buffers:

Solvent: 20% ethanol

5% Glutaraldehyde solution: add 5ml of 25% aqueous glutaraldehyde solution to 20ml of Coupling Buffer.

Coupling Solution: 10mM pyridine (Add 0.8ml of pyridine to 900ml of water. Adjust the pH to 6 with HCL. Add water to a final volume of 1L.)

Quenching Solution: 1.0M glycine (Dissolve 7.5g of glycine in 90ml of water. Adjust the pH to 8 with 10N NaOH. Add water to a final volume of 100ml.)

Washing Buffer: 0.01 M Tris base containing 0.15 M NaCl, 0.1% (w/v) BSA, 0.001M EDTA, sodium salt and 0.1% (w/v) sodium azide (Dissolve 1.21g of Tris base, 8.7g of NaCl, 1g of BSA, 0.37g of EDTA, sodium salt and 1.0g of sodium azide in 900ml of water. Adjust the pH to 7.4 with HCl. Add water to a final volume of 1L.)



Sample Preparation

1. Dissolve 1-10mg protein/peptide in 0.5-1ml coupling buffer. Protein concentration is typically 1-10mg/ml. 

2. If samples have already suspended in other buffers, dilute samples with an equal volume of coupling buffer.

Bead activation

1. Gently mix the magnetic beads thoroughly before use by shaking.

2. Place 1mg of magnetic beads into a microcentrifuge tube.

3. lace the tube into a magnetic stand, collet the beads, and discard the supernatant.

4. Wash the beads three times with Coupling Buffer (1ml each time) by magnetic separation.

5. Re-suspend the beads by adding 400ul of 5% Glutaraldejhude and shake. Incubate at room temperature for 3 hrs with gentle rotation.

6. Separate beads using a mganet, remove the supernatant.

7. Wash beads three times with 1ml Coupling Buffer to remove unreacted glutaraldehyd.

Protein Coupling

1. Add 200ul protein solution into the tube containing activated beads and mi well by shaking. Incubate for 24 hrs at room temperature or 4°C with gentle rotation.

2. Separate beads using a magnet, remove the supernatant.

3. Add 800ul of Quenching Solution into the tube. Shake to suspend the beads. Gently shake for 30min at room temperature.

4. Wash the beads with a 1ml Washing buffer three times.

5. Suspend the beads with the desired volume of washing buffer or in a buffer compatible with the attached protein. Store at 4°C until ready for use.

Important Notes

1. This protocol can be used for both coupling primary amine-containing and carboxy-containing ligands.

2. The coupling buffer should not contain any amino (e.g., Tris) or carboxyl groups (e.g., acetate and citrate).

3. The solutions containing glutaraldehyde or pyridine are volatile and harmful. Please perform operations with these solutions in a chemical fume hood.

4. Protein and bead concentrations should be optimized. Too low a protein concentration may result in bead crosslinking.

5. Do not freeze, dry, or centrifuge at high speed during the use or storage of beads. Otherwise, this may decrease the binding capacity of the beads.

The product is not thoroughly tested and is not intended for human use. For in-vitro and research use only.
  • 17 Units in Stock

Ask a Question

$576.00 $320.00Save: 44% off

Add to Cart:
LifeTein LifeTein provides custom peptide synthesis service, recombinant proteins, peptides, cytokines, custom antibody service and custom protein service. LifeTein is the world leader in fast peptide synthesis service with lab facility located in New Jersey USA. LifeTein Peptide 100 Randolph Road, Suite 2D, Somerset USA New Jersey 08873
Copyright © 2024 LifeTein.com. Powered by LifeTein